/*
 * Copyright 2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.cloud.stream.binder.rocket.utils;

import java.io.UnsupportedEncodingException;

/**
 * @author Xi Ning Wang
 */
public final class RocketMQTopicUtils {

    private RocketMQTopicUtils() {

    }

    /**
     * Allowed chars are ASCII alphanumerics, '.', '_' and '-'.
     */
    public static void validateTopicName(String topicName) {
        try {
            byte[] utf8 = topicName.getBytes("UTF-8");
            for (byte b : utf8) {
                if (!((b >= 'a') && (b <= 'z') || (b >= 'A') && (b <= 'Z') || (b >= '0') && (b <= '9') || (b == '.')
                        || (b == '-') || (b == '_'))) {
                    throw new IllegalArgumentException(
                            "Topic name can only have ASCII alphanumerics, '.', '_' and '-', but was: '" + topicName
                                    + "'");
                }
            }
        } catch (UnsupportedEncodingException e) {
            throw new AssertionError(e); // Can't happen
        }
    }
}
